A plastic liner or the like is oftentimes employed in a shipping carton or box to retain foodstuffs or other commodities in a fresh condition therein. The liner is usually in bag form and is manually inserted into the carton by a workman. Such a manual method of applying the liner interiorly of the carton is laborious and time consuming. In addition, a workman having a low degree of dexterity may find it difficult to place the liner in its proper position within the carton to fully cover the interior walls thereof and to avoid any undesirable wrinkles or folds in the liner.